<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        var a = 13;
        alert(a);
        function f1() {
        // var i = 123;
            i = 123;
        }
        f1();
        alert(i)
    </script>
</head>
<body>

</body>
</html>